Conventionally, such sealing device is known, for example, in Japanese Unexamined Patent Application Publication No. 2006-57825. In the sealing device, a sealing structure is known having a rotating seal member 2 known-as a deflector, fixed to a rotary shaft 1, and a fixed seal member 4 fixed to an inner surface of a shaft hole 3 in which the rotary shaft 1 is disposed, as illustrated in FIG. 12. The rotating seal member 2 is formed from a rigid body, and the fixed seal member 4 has a compound structure of a rigid body and an elastic body.
This kind of sealing device is used in a driving system unit or other apparatus of a vehicle such as, for example, an automobile. While the fixed seal member 4 mainly seals a lubricant in a machine internal space S, the rotating seal member 2 mainly prevents the infiltration of foreign substances such as mud or dust from the outside of the machine A to the machine internal space S.
The fixed sealing member 4 has a seal lip 4A and a side dust lip 4B that contact the rotary shaft, and an axial dust lip 4C the contacts the rotating seal member 2. The seal lip 4A mainly has the role of sealing lubricant in the machine internal space S, and the dust lips 4B and 4C mainly have the role of preventing the infiltration of foreign substances from the outside of the machine A to the machine internal space S.